* shared.h (class pinfo): New members root' and rootlen'.

* syscalls.cc (chroot): Set new root for process.
        * path.cc (getcwd_inner): Add parameter to force use of
        new root from chroot() call.
        (ischrootpath): New macro.
        (normalize_posix_path): Care for changed root dir.
        (normalize_win32_path): Ditto.
        (getcwd_inner): Ditto.
        (chdir): Eliminate trailing path component consisting
        entirely of dots.
        * fork.cc (fork): Copy pinfo members regarding chroot().
        * spawn.cc (_spawnve): Ditto.
        * dir.cc (opendir): Don't use computed win32 path if
        chroot() took place.

winsup/cygwin/shared.h

@@ -102,6 +102,11 @@ class pinfo
   uid_t real_uid;        /* Remains intact on seteuid, replaced by setuid */
   gid_t real_gid;	 /* Ditto */
 
+  /* Filled when chroot() is called by the process or one of it's parents.
+     Saved without trailing backslash. */
+  char root[MAX_PATH+1];
+  size_t rootlen;
+
   /* Non-zero if process was stopped by a signal. */
   char stopsig;